How to properly implement the Equatable protocol in a class hierarchy?

Question

I\'m trying to implement the == operator (from Equatable) in a base class and its subclasses in Swift 3. All of the classes will only be used in Sw

Answer 1

Following rmaddy's answer, I came up with a guard approach for testing equality:

Base.swift

---

static func ==(lhs: Base, rhs: Base) -> Bool {
    // ensure class properties match
    guard lhs.x == rhs.x else {
        return false
    }

    return true

}

Subclass.swift

---

static func ==(lhs: Subclass, rhs: Subclass) -> Bool {
    // ensure base class properties match
    guard lhs as Base == rhs as Base else {
        return false
    }

    // ensure class properties match
    guard lhs.y == rhs.y else {
        return false
    }

    return true
}

```